Update firewall config for docker usage

playbooks/configure-docker.yml

@@ -1,16 +1,23 @@
 ---
-- import_playbook: meta.yml
-
 - name: Configure docker hosts
   hosts: servers
   roles:
     - role: docker
   tasks:
-    - name: Disable firewall on internal interface
+    - name: Allow swarm traffic through the firewall
       become: true
       firewalld:
         state: enabled
         service: docker-swarm
+        zone: public
+        permanent: true
+        immediate: true
+    - name: Disable firewall on docker bridge interface
+      become: true
+      firewalld:
+        state: enabled
+        interface: docker0
+        zone: trusted
         permanent: true
         immediate: true